1. Field of the Invention
The present invention relates to an electronic controlled suspension apparatus and a vehicle height control method thereof, and more particularly, to an electronic controlled suspension apparatus capable of stopping vehicle height control when a vehicle turns and performing the vehicle height control when the vehicle goes straight ahead by using vehicle height sensors instead of a steering angle sensor, and a vehicle height control method of the electronic controlled suspension apparatus.
2. Description of the Related Art
Generally, an electronic controlled air suspension apparatus is an apparatus for controlling the height of a vehicle using an air spring capable of controlling internal pressure of a suspension apparatus of the vehicle, instead of a conventional coil spring.
The operation of controlling a vehicle to be at a height that a driver desires using such an electronic controlled air suspension apparatus should be performed when the vehicle is in a driving state as well as in a stop state. However, since the distance between a vehicle body and a road wheel varies depending on a slope of a road surface and movement of the vehicle, the control of the vehicle height when the vehicle is in a driving state is very difficult as compared with the vehicle in a stop state.
Such an electronic controlled air suspension apparatus, which is mounted between the vehicle body and the road wheel, receives vehicle height signals from vehicle height sensors detecting actual height of the vehicle and filters the signals using a low pass filter, thereby removing inaccuracy of the vehicle height control occurring due to the slope of the road surface and the vibration of the vehicle body. However, the inaccuracy of the vehicle height control occurring due to the height difference between the left and right sides of the vehicle when the vehicle turns can be removed only when installing an additional sensor, such as a steering angle sensor or the like.
The steering angle sensor mounted to the steering wheel of a vehicle is a sensor that detects how much a driver intends to steer the vehicle, through which the intention of the driver to change the direction of the vehicle can be known before the movement of the vehicle begins to be changed.
Accordingly, even when air is injected in and discharged from an electronic controlled air suspension apparatus in which a steering angle sensor is employed, the vehicle height control is temporarily stopped before the movement of the vehicle begins to be changed, and is resumed after the vehicle terminates to turn, thereby removing the inaccuracy of the vehicle height control occurring due to the turn of the vehicle.
However, if a steering angle sensor is used only to remove the inaccuracy of the vehicle height control occurring when the vehicle turns, the manufacturing costs of the system is unnecessarily increased.